Tippy-tippy Tap…

The last few weeks have been a time of looking closely at flowers, and marvelling at their variety. I observed about 12 types of pink flowers, about 8-10 types of orange flowers, about 5-6 red, a few yellow ones, a few white ones and two types each of purple flowers and blue flowers–all in my colony. 

So of course the question came to my mind: Was this the typical distribution of flower colours? Was pink the predominant colour, followed by orange and red? And so started my search to find out a little more about this.

First and foremost, what gives flowers their colours? Colours mainly come from the presence of pigments in the chromoplasts or cell vacuoles of floral tissues.  The most common pigments in flowers come in the form of anthocyanins which range in colour from white to red to blue to yellow to purple and to even black and brown. The other major group are the carotenoids, which provide the yellow colours, along with some oranges and reds. While many flowers get their colours from either anthocyanins or carotenoids, there are some that can get their colours from a combination of the two. Other classes of pigments, but of less importance in relation to flower pigmentation, are chlorophylls (greens), quinones (occasional reds and yellows), and betalain alkaloids (giving yellow, red and purple). 

Coming back to which is the most common flower colour, all my web- searching only told me that there was no definitive answer! To begin with, we don’t even know how many flowering plants there are. And of the flowers we know and have catalogued, colour data are seldom maintained. There is no repository of flower colour information. There is no database which documents flower colours, let alone rank them.

There are many good reasons that make it difficult to document these colours. There is no absolute measure. Colours look different in different lights, at different times of the day. Each person perceives colour differently—what looks orange to me look yellow to you. And we all describe them differently—I may say violet for a colour and you may say mauve.

Moreover, colours vary from genus to genus, and even within a species. A plant growing in one area (say, the plains) can have flowers  that are very different from the same plant growing elsewhere (say in higher altitudes). The colours of flowers depend very much on the growing conditions—soil, sunlight etc. So they may change somewhat with season too.

Recent research suggests that factors like ozone depletion and global warming have caused flowers to change their colours over time. For instance, of the 42 species studied in that research, UV-pigmentation in flowers increased at a rate of 2% per year from 1941 to 2017.

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Lantana is one of the flowers which changes colour on pollination

Flowers also use colours as signalling mechanisms. Some flowers change their colour once they are pollinated, so that bees do not come back to them, but rather go to unpollinated flowers. (Eminent teacher, Prof. Mohan Ram, who developed a generation of botanists, ecologists and environmentalists, taught us this during a memorable nature walk.) Some flowers change their colour with age.

But here are some speculations about flower colours:

Counter-intuitively, some people believe green may actually be the most common flower colour–many plants, including most trees, bear flowers in various shades of green. This may be followed by white, yellow, blue and the reds in that order.  Brown is not uncommon either. But all scientists and naturalists emphasize that these are only guesses.

So don’t worry too much about how many. Just enjoy the flowers and their colours!

–Meena

A Magical Walk

I remember it well—a mere 400 metre walk on our office campus in Ahmedabad. That day we were walking along the path that all of us took regularly; walking along with us was Professor HY Mohan Ram, a member of our Governing Council, who was there for the Council meeting. As we walked, Professor Mohan Ram talked—gently, softly, but with passion and excitement, pointing out plants that we saw every day, but, as we realised, we never really ‘looked at’.

“Look at this one”, he pointed at a plant, “this is Aduso. Its botanical name is Adhatoda vasika which means ‘that which the goat will not touch’. This is what is used for making medicines for cough and cold.” Going just two steps ahead, “You know the cactus, but did you know that there is not a single native cactus in the whole of Asia and Europe? All cactii are from the New World—Mexico, North America and South America.” ”Look at this magnificent neem tree.  Its botanical name Azadirachta indica comes from the Arabic for azad meaning ‘free’ and drakhta meaning ‘tree’. This is thought to be a tree indigenous to India, but there is some doubt if it is originally Indian. It may have originated on the Burma border and come to Bangladesh from there.” “Did you know that Lutyens, when planning the landscaping of Delhi’s roads, planted only native species. Each avenue was planted with one species of fruit tree.” Three steps ahead, we come to the white flower commonly called Chandni. Professor tells us, “Have you noted carefully the arrangement of petals of flowers? Most flower petals are usually in multiples of 3 or 5 (except in the case of the mustard flower).” “Many high school students know this as the shoe flower that they got for dissection in the exams. But why the name shoe flower? Because it is used to polish shoes! Its other name is hibiscus, and is believed to have originated in China.”

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Professor HYM had a fascinating story for every step that we took, drawing attention to the tiniest of flowers that we carelessly trampled underfoot, to the towering culms of bamboo. The path that took us 5-7 minutes to traverse became a magical mystery tour that took close to two hours. Through his eyes the blur of vegetation turned into a veritable treasure trove, with each plant glowing with its own special attributes.

Not long after this visit, Meena and I invited Professor HYM to contribute to a collection of tales of ‘Nature Heroes’ that we were putting together. He graciously agreed, and shared with us some of his journey, experiences and inspirations in a piece titled Reflections of a Botanist.  He writes “I have not pursued any single course. I have done what interests me and not what is in style. I have a deep interest in Indian classical music and photography.”

He concludes the piece with this, “What enlightenment have I received as a student of plant biology? I wish I could be like a tree: deep-rooted and firmly fixed, bearing a lofty bole and a broad canopy, continuously absorbing, synthesizing and renewing, unmindful of stresses and insults, resilient to changes and perpetually giving.”

In the passing away of Professor HY Mohan Ram the world has lost not only a botanist par excellence, but a much loved and respected teacher, researcher, and writer. For us, the Matriarchs, Professor Mohan Ram will always be remembered as a gentle, unassuming guide with a twinkle in his eyes, and a life-long inspiration whose visits to the Centre were like the Open Sesame to a fascinating world of flora.

A page from my notes on the Walk!  (Date 22 August 1998)

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–Mamata